The crankshaft of a machine press is oriented horizontally to harness the power to drive an automated device. The horizontal orientation is for reasons of position, rotational direction, and other factors. The crankshaft is integrated with a connecting rod so as to form a crank mechanism. In such cases, one drawback is that the connecting rod undulates vertically. Furthermore, vertical movement by the connecting rod causes the thrust load to be displaced vertically. To compensate for the displacement of the thrust load, the frame of the machine press is required to be much stronger longitudinally, usually by increasing the thickness of the press, so as to assure sufficient rigidity.
In multiprocess pressing, multiple processes are in general arranged side-by-side, and work pieces are fed from mold to mold laterally. The extent of the process load varies between processes this causes an eccentric load to occur in the frame in the lateral directions. The eccentric load acts on the frame as thrust load in the lateral directions, thus requiring the frame to have sufficient lateral rigidity.
To address both the longitudinal thrust load caused by undulation of the connecting rod and the lateral eccentric load caused by the press load, the frame of a machine press must be provided with sufficient rigidity in both the longitudinal and lateral directions. This is illustrated in the prior art. FIG. 3 of Unexamined Patent Application H8-174295 illustrates a frame having a thick shape longitudinally.